[en] A short review is given of the empirical evidence and theoretical interpretation of baryonium. (orig.)

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[en] A point of common interest for both dibaryons - bound or resonant states of two baryons - and baryonia (mesons coupled predominantly to the baryon-antibaryon channel and much lesser to the mesonic ones), is a question mark about their nature; whether they are resonant states due to long- or medium-range meson exchange conventional forces, or short-range color forces of 'non-conventional' nature. This lecture summarizes more than twenty years of theoretical and experimental activity on this subject. 123 refs.; 19 figs.; 5 tabs

[en] The existing experimental information on baryonium is compared in detail with the predictions of the diquark-antidiquark colour molecular (diquonium) model. The correspondence is found encouraging and close to a confirmation of colour as a genuine degree of freedom in hadron specroscopy

[en] An attempt is made to summarize the experimental status of narrow B anti B states as of mid-1979. In particular, concentration is placed on the current experimental situations and prospects regarding three serious contenders for the so-called baryonium states. Theoretical concepts of baryoniums, narrow N anti N states known as S(1935), anti pp(2020), and anti pp(2204), and some forthcoming results, and problems of the above three resonances are discussed. 31 references

[en] A brief review on the aspects of baryonium related to general properties of the baryon-antibaryon interaction is given

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[en] The mass spectrum of diquark-antiquark is studied. The strong spin-spin force between two quarks inside a diquark causes a large mass splitting of about 200 MeV. The electromagnetic mass splitting of these mesons is also studied

[en] Various theoretical interpretations of narrow hadron states unconnected with new flavours are reviewed, with special emphasis on narrow baryoniums above the N anti N threshold which are believed to be indicative of a new phenomenon, due probably to colour, never before realized in hadron spectroscopy. (orig.)